2011 Chevrolet Express 1500 Cargo Owner's Manual - Page 299

Vehicle Care 10-29 Brake Fluid Do not top off the brake fluid. Adding fluid does not correct a leak. If fluid is added when the linings are worn, there will be too much fluid when new brake linings are installed. Add or remove brake fluid, as necessary, only when work is done on the brake hydraulic system. Refer to the Maintenance Schedule to determine when to check the brake fluid. See Scheduled Maintenance on page 11‑3. Checking Brake Fluid Check brake fluid by looking at the brake fluid reservoir. See Engine Compartment Overview on page 10‑6. The brake master cylinder reservoir is filled with DOT 3 brake fluid. See Engine Compartment Overview on page 10‑6 for the location of the reservoir. There are only two reasons why the brake fluid level in the reservoir might go down: . { WARNING If too much brake fluid is added, it can spill on the engine and/or fuel operated heater parts, if equipped. If the vehicle has a diesel engine and a fuel operated heater, see "Fuel Operated Heater (FOH)" in the diesel engine supplement. The fluid will burn if the engine is hot enough. You or others could be burned, and the vehicle could be damaged. Add brake fluid only when work is done on the brake hydraulic system. See "Checking Brake Fluid" in this section. The brake fluid level goes down because of normal brake lining wear. When new linings are installed, the fluid level goes back up. A fluid leak in the brake hydraulic system can also cause a low fluid level. Have the brake hydraulic system fixed, since a leak means that sooner or later the brakes will not work well. . The fluid level should be above MIN. If it is not, have the brake hydraulic system checked to see if there is a leak.